Experimental study and correlation on the falling column adiabatic absorption of water vapor into LiBr-H2O solution

A new kind of LiBr-H2O absorption process, the falling column adiabatic absorption, is presented and discussed in this paper. Different from the traditional absorption, this process can separate heat and mass transfer process with external cooling; besides, the solution flows through orifices by gravity and does not need any mechanical energy for solution distribution. Experiments were carried out to study the mass transfer process of the falling column absorption. Mass transfer coefficients for different conditions were defined and calculated by an analysis model. The mass transfer coefficients that were found range from 1 × 10−4 to 3 × 10−4 m s−1 under experimental conditions. An experimental correlation of mass transfer coefficient was developed as a function of the mass diffusivity and column diameter with an error band of 15%. Falling column configurations were proved to have good performance and can be an alternative to existing ones.